Terratec TBM S97, named Podhigai, along with six other TBMs will build approximately 9km of twin tunnels – 18km in total – for Corridor-3, extending from Venugopal Nagar Station to Kelly’s Station. Terratec is supplying five of the seven TBMs required for the package, and commenced dispatch in 2022.
Three other TBMs have also broken through this year. TBM S96, launched in October last year, achieved its breakthrough in August at Madhavaran High Road, while TBM S98 made its breakthrough in June, moving from the same shaft at Madhavaran Colony towards Venugopal Nagar Station (of Line 5) to Kelly’s Station. The breakthrough of TBM S99 at Venugopal Nagar Station was celebrated in September.
Package TU-01 includes the construction of diaphragm walls and entry and exit structures for Madhavaram Milk Colony Station, Murari Hospital Station, Ayanavaram Station, and Purasaiwakkam High Road Station, and launch and retrieval shafts. One of the project’s major challenges is tunnelling beneath historical structures in densely populated areas.
Terratec’s TBMs are equipped with mixed-ground dome-style cutterheads to handle a range of geology, such as sand, silt, clay, and weathered rock. The TBMs progress with the installation of 1,400mm-wide and 275mm-thick universal reinforced concrete lining rings, comprising five segments and a key.
